1. Field of the Invention
The present invention relates to an improved refrigeration subcooler comprising an accumulator and receiver apparatus for use in a refrigeration unit or heat pump. Specifically, the present invention relates to a subcooler that requires less refrigerant and is operable at lower operating pressures than conventional subcoolers.
2. Description of the Prior Art
The use of a heat exchanger comprising an outer housing that functions as an accumulator and an inner housing that functions as a receiver is well known in the refrigeration art. Such heat exchangers are known as "subcoolers." Such a subcooler is disclosed in U.S. Pat. No. 4,236,381 to Imral, et al. In prior art subcoolers, the accumulator is installed in the suction line of a compressor used in the refrigeration cycle for the purpose of preventing the introduction of liquid slugs or other impurities into the suction line of the compressor. The use of a filter medium, comprising desiccant, can be used in such receivers to facilitate the purification and/or drying of the refrigerant. The outer casing or accumulator stores liquid refrigerant.
Prior art refrigeration units commonly use refrigerants containing chlorofluorocarbons ("CFCs"). CFCs are known to have an adverse effect upon the environment. Accordingly, federal environmental regulations have been enacted which are aimed at reducing the release of CFCs into the environment.
After extended use, the filter and/or desiccant medium in a conventional receiver must be replaced. In the case where the refrigerant contains CFCs, the refrigerant must be evacuated from the system in many prior art accumulators/receivers before the filter and/or desiccant medium can be replaced. This evacuation process is costly and time consuming. One improvement of the present invention is the elimination of the need to evacuate system refrigerant prior to changing the filter medium in order to avoid the release of CFCs into the environment.
The accumulator/receiver of the present invention is also designed to operate with less refrigerant than prior art accumulators/receivers, thereby allowing greater energy conservation and lower operating pressures. Additionally, the accumulator/receiver of the present invention is designed to provide superior heat transfer and condensing capabilities over prior art accumulators/receivers.